CM Punk returns to Cleveland’s Quicken Loans Arena this Saturday for UFC 203, the first time he will step in the building since he walked out on Vince McMahon before Raw on January 27, 2014.

Despite the fact that Punk has not wrestled in nearly three years—and is a mere two days away from making his debut in the Octagon—the disciplines of pro wrestling and pro fighting continue to intertwine in his life.

While Punk is finished with WWE, he is open to the idea of wrestling for New Japan Pro Wrestling.

“A long time ago I stopped saying ‘never,’ but that’s a loaded question,” Punk explained. “I don’t know the answer. No matter what I say, it’s going to take on a life of its own.”

Punk turns 38 in October. Although both Punk and UFC president Dana White have publicly stated that he has a multi-fight UFC contract, there is no defeating Father Time in the cage. Punk’s age, however, would not hinder him in pro wrestling, and the chance to compete in Japan would fulfill his boyhood dream.

“When I started wrestling, I never wanted to go to WWE,” said Punk, who wrestled in Japan in 2003 for Pro Wrestling Zero1. “It was the Japanese life for me. I romanticized guys, like [Eddie] Guerrero, [Chris] Benoit, [Chris] Jericho, who went over there, and it just sounded like such an awesome life. You’d go over there for two, three, four weeks, and you come back and nobody knows who the f--- you are. I could go get ice cream with my sisters without being harassed, and that was always my style.”

Punk’s fight with Mickey Gall is only two days away, but his battle began the moment he signed with UFC. His UFC signing, announced by Dana White on December 6, 2014 at UFC 181, set off a firestorm of criticism.

The rush to judge bothered Punk but did not crack him. In fact, the same doubt was cast on him thirteen years ago while wrestling in Japan.

“One of the biggest moments for me was when I wrestled in Japan, and I was told I was too small to be a heavyweight and too big to be a cruiserweight,” said Punk. “I remember thinking, ‘What the f--- do I do now? This was my dream.’ So I re-evaluated and got new goals, and I could have quit then but I didn’t.

“It’s just like fighting. It’s something I want to do, people laugh and say ‘you can’t do it,’ and then I think, ‘Why should I believe you?’ and I go out and do it. Things that you learn along the way and things that you gain, it’s all positive. I could think of awful stories when I didn’t think I’d survive the night, and now I’ve learned from it and grown from it.”

Undeterred, Punk continues to move forward by training and refusing to allow the self-doubt of others to cripple him.

“I’m a polarizing person, so people get caught up in hoping I fail,” said Punk. “And just like success, failure is a perspective. If I go out there and lose a split decision, then I lost the fight. But did I fail? I don’t know. Everybody has a different perspective.

“Winning is different based on your perspective, just like success is different based on your perspective. I’m not sure how often I win at things. To me, just doing this is winning. I don’t think about shocking the world or changing everybody’s mind, but I just think about going out there and doing what I was taught to do and showing people that, if you want to do something, then work hard at it and it can be done.”

Punk remains an unproven commodity in mixed martial arts, but he is arguably the most compelling box office attraction in wrestling. Even after an arduous training camp, led by Roufusport’s renowned MMA expert Duke Roufus, Punk admits that the grind of pro wrestling is far more taxing on the mind, body, and soul than fighting.

“If I come in here on a day and I’m not feeling it, and if I wasn’t in camp, I would look at everybody and say, ‘You know what guys? Not today,’” said Punk. “I’d go home and rest, but you can’t do that in wrestling. You get off the plane, load up on coffee—or whatever stimulants (when the reporter mentioned to the colorfully tattooed Punk that his stimulant of choice is Pepsi Cola, he replied, “Some people like coke, if you know what I mean”), and it’s just go, go, go, go, go, go.

“It’s a lifestyle you’ve got to do when you’re younger. I got too f------ old for it. I was sick of it. I met my wife, and it’s not a life conducive of happiness, at least in my opinion. I wasn’t happy, now I’m happy. I can come in here and I can still feel like s---, and I can still get something done and learn something, then sleep in my own bed every day. Comparing the two are apples to oranges. You can find parallels and comparisons, but they’re two different animals.”

Punk is still capable of cutting the sharpest promo in sports, which will be on display with a victory this Saturday—he is, after all, the originator of the “Mic Drop”—but he is also extremely humble and gracious. His humility was on display as he expressed his gratefulness for his time in pro wrestling and the opportunities it continues to provide him.

“Of course I’m happy with my time in professional wrestling,” said Punk. “I met some great people, I met my wife, and I wouldn’t trade it for the world.”

Evolving from a career in the sports entertainment business to a crash course in the unforgiving reality of mixed martial arts—which, in Punk’s case, happened practically overnight—is no easy task.

“The only thing I can touch on that is sometimes I’m too nice in the cage,” said Punk. “Sometimes I’m still in pro wrestling mode. Instead of snatching an arm right away, I’m not cranking on it as much as I should, which would end a fight. But there’s also been situations where I’ve been put in a sparring situation and my head is in the right spot.”

Punk’s job in wrestling was to make punches look stiff and believable while protecting his opponent, which completely contradicts his goal in the cage—to knock out his opponent—even if it is accomplished in a beastly manner.

“I think this will always be a problem,” said Punk. “Coach Cush [Scott Cushman] says, all the time, that I want things to be too pretty – I want to throw perfect punches all the time. This is a fight, and sometimes my coaches have to grab me and say, ‘Get gnarly! What’s a perfect punch? One that lands.’ So that’s the one I need to throw, and f--- it, I know it ain’t going to be perfect.”

Punk has spent every conceivable moment of his life over the past two years training and preparing for his fight, and he has neither the time nor the interest to watch Raw every Monday. There is no one in wrestling, Punk commented, who reminds him of himself in the ring.

“Everybody is their own self,” said Punk. “I think there’s maybe hints of me here and there, and whether that’s they’re trying to emulate me, or they’re just good and maybe I was good too, I don’t know, but I definitely don’t take credit for anyone’s hard work.

“I was the guy that championed all the guys in developmental. Whether people there want to admit it or not, I helped a lot of guys A, get hired, and B, get called up. It was because I knew they were good, so it wasn’t just because of what I said that got them to where they are. It was them, but I was one of the first guys to shed a light on that and say, ‘F--- it, these are the guys that are good.’ When I was where these guys are, no one would do that for me. I really felt like I needed to be different from a lot of the top guys that were around when I got called up.”

Punk has traveled an unconventional route, but conventions were made to be challenged. He plans on winning Saturday’s fight, but the idea of failure does not prevent him pursuing his goal of victory.

“People expect me to get knocked out, people expect me to get starched in thirty seconds,” said Punk. “The people who know me, who see me work every day, they expect me to win. You can ask yourself, ‘What happens if I lose? What happens if I get embarrassed in front of the world?’ Then you think to yourself, ‘Well, you sh-- yourself on national television before,’ so how bad can this really be? I tend to think of this entire journey as a discovery about myself more than it is the final destination.”

Throughout the entire journey, Punk has held on tightly to his sense of humor. Even if the fight ends in a loss, Punk explained, he will be thrilled that his dog, Larry, who made sporadic appearances on UFC’s “The Evolution of Punk” documentary, is now television-famous.

“I like to say Larry is from outer space,” said Punk. “We DNA tested him, and they broke the machine. He came back a whole bunch of different dogs. We rescued him from a place in Chicago called PAWS, a great no-kill shelter. He’s a mutt.”

Ironically, Punk also noted that the jump from pro wrestling—derided by critics as phony and fake—to pro fighting, which is championed as real, actually allowed his body to heal from a seemingly omnipresent array of injuries, most notably a herniated disk in his back.

“If I never did this, I’d still be walking around with a herniated disk,” said Punk. “The thing about being a wrestler is you’re your own worst enemy. You just keep going. I was in here every day, and I just kept going and kept going. I made excuses like, ‘My back is just sore. These guys are just better than me. They’re faster than me. Maybe I’m just getting old and not as strong as I used to be.’ Once I was diagnosed with a herniated disk, it wasn’t like I could get a shot to fix it. I had to get it cut out of me. It wasn’t disappointment or depression, I was elated.

“Once I came back in the gym, I was a completely different person. So what’s the worst thing that can happen? The worst thing that can happen is I had back surgery and feel like my old self again, and my dog is all over television. I just look at things differently than everybody. I was operating on twenty-five percent power.”

While Punk was unwilling to make the comparison, UFC fighters such as Conor McGregor often view their brethren in pro wrestling in the same disrespectful manner as Goliath thought of David. A nation of wrestlers turns their lonely eyes to Punk to stand up for the business of professional wrestling in his UFC debut. New Japan’s Rocky Romero was one friend, Punk noted, who has offered nothing but support.

“If I decided to be a farmer, Rocky would be pulling for me,” said Punk. “I’ve known Rocky, I don’t know how long, and there were a bunch of us who frequented the New Japan dojo that remain in contact – Samoa Joe, guys like that. I think, just because I’m that polarizing guy, there are going to be people in the wrestling world who are going to laugh, regardless of what happens, and there are people who are pulling for me. I tend to lean towards the support, and I do appreciate it.”

Wrestling does not solely define Punk, who is also a comic book author, a champion for the Make-A-Wish Foundation, and a lover—not to mention fighter.

“I spar with the toughest team in America,” said Punk. “I’m ready. A lot of people have misgivings about what it takes to fight, and that’s the most important word to me, fight. I don’t care if someone wants to make fun of my technique or that my right hand isn’t as crisp as it should be, because it’s going to land. And that’s what I care about, the punch that lands.”

Punk would not reveal his entrance music for this Saturday, but did share that Brock Lesnar reached out with support after he first announced his decision to fight.

“He reached out and offered his help and his support,” said Punk. “He lives in the middle of nowhere in Saskatchewan, and I texted him once and it bounced back to me right away.”

Punk took no joy when he learned about Lesnar’s doping violations.

“I think it sucks,” said Punk. “I get tested by USADA all the time, and I’m the drug-free kid. It’s like when you’re driving on the highway and the cop is behind you – ‘Well, I wasn’t speeding, and my taillight isn’t out, but let me slow down.’ The whole thing bums me out. Brock came back, he fought an impressive fight and won, and then he failed a test. It bums me out when anybody fails a test.”

While Mickey Gall is extremely dangerous, Punks knows he faces a tougher opponent every day from the man in the mirror.

“Without sounding disrespectful to him, this is my story,” said Punk. “This is about me wanting and almost needing to do something just to prove to myself that I can. There are people out there who hope I lose, and there are those who realize that, once I step into the Octagon, I’ve already won. For me, it’s not about the destination, it’s all about the journey.”

Punk offered a piece of advice to those who continue to question his heart.

“Don’t be so negative,” said Punk. “Whether you want to admit it or not, there is something in your life that you want to pursue that you’re afraid of – don’t be afraid of it. Don’t be so negative. Haters only hate up, no one is ever worried about someone below them. They’re not talking s--- about people below them. When people see somebody going for what they want and living this dream, that’s when they hate on it. Just level up and focus on yourself.”

As for Punk’s dream, he sees this fight ending in only one way.

“My expectations are to win,” said Punk. “Go out there, whether it goes three rounds or three seconds, and get my hand raised.”

More Extra Mustard

We've Got Apps Too

Get expert analysis, unrivaled access, and the award-winning storytelling only SI can provide — from Peter King, Tom Verducci, Lee Jenkins, Grant Wahl, Andy Staples and more — delivered straight to you, along with up-to-the-minute news and live scores.